// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MEDIA_AUDIO_ALSA_AUDIO_MANAGER_ALSA_H_
#define MEDIA_AUDIO_ALSA_AUDIO_MANAGER_ALSA_H_

#include <memory>
#include <string>

#include "base/compiler_specific.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/threading/thread.h"
#include "media/audio/audio_manager_base.h"

namespace media {

class AlsaWrapper;

class MEDIA_EXPORT AudioManagerAlsa : public AudioManagerBase {
public:
    AudioManagerAlsa(
        scoped_refptr<base::SingleThreadTaskRunner> task_runner,
        scoped_refptr<base::SingleThreadTaskRunner> worker_task_runner,
        AudioLogFactory* audio_log_factory);

    static void ShowLinuxAudioInputSettings();

    // Implementation of AudioManager.
    bool HasAudioOutputDevices() override;
    bool HasAudioInputDevices() override;
    void ShowAudioInputSettings() override;
    void GetAudioInputDeviceNames(AudioDeviceNames* device_names) override;
    void GetAudioOutputDeviceNames(AudioDeviceNames* device_names) override;
    AudioParameters GetInputStreamParameters(
        const std::string& device_id) override;
    const char* GetName() override;

    // Implementation of AudioManagerBase.
    AudioOutputStream* MakeLinearOutputStream(
        const AudioParameters& params,
        const LogCallback& log_callback) override;
    AudioOutputStream* MakeLowLatencyOutputStream(
        const AudioParameters& params,
        const std::string& device_id,
        const LogCallback& log_callback) override;
    AudioInputStream* MakeLinearInputStream(
        const AudioParameters& params,
        const std::string& device_id,
        const LogCallback& log_callback) override;
    AudioInputStream* MakeLowLatencyInputStream(
        const AudioParameters& params,
        const std::string& device_id,
        const LogCallback& log_callback) override;

protected:
    ~AudioManagerAlsa() override;

    AudioParameters GetPreferredOutputStreamParameters(
        const std::string& output_device_id,
        const AudioParameters& input_params) override;

private:
    enum StreamType {
        kStreamPlayback = 0,
        kStreamCapture,
    };

    // Gets a list of available ALSA devices.
    void GetAlsaAudioDevices(StreamType type, AudioDeviceNames* device_names);

    // Gets the ALSA devices' names and ids that support streams of the
    // given type.
    void GetAlsaDevicesInfo(StreamType type,
        void** hint,
        AudioDeviceNames* device_names);

    // Checks if the specific ALSA device is available.
    static bool IsAlsaDeviceAvailable(StreamType type,
        const char* device_name);

    static const char* UnwantedDeviceTypeWhenEnumerating(
        StreamType wanted_type);

    // Returns true if a device is present for the given stream type.
    bool HasAnyAlsaAudioDevice(StreamType stream);

    // Called by MakeLinearOutputStream and MakeLowLatencyOutputStream.
    AudioOutputStream* MakeOutputStream(const AudioParameters& params);

    // Called by MakeLinearInputStream and MakeLowLatencyInputStream.
    AudioInputStream* MakeInputStream(const AudioParameters& params,
        const std::string& device_id);

    std::unique_ptr<AlsaWrapper> wrapper_;

    DISALLOW_COPY_AND_ASSIGN(AudioManagerAlsa);
};

} // namespace media

#endif // MEDIA_AUDIO_ALSA_AUDIO_MANAGER_ALSA_H_
